Izoni dies, triggering Nim Deathmantle, causing you to pay ({4} magic symbol) to return Izoni from your graveyard to the battlefield, and attach Nim Deathmantle to it.
Izoni enters the battlefield, creating at least four 1/1 Insect creature tokens.
Activate Phyrexian Altar three times by sacrificing three Insects, adding ({3} magic symbol) .
Repeat.
Once you have infinite creature tokens and mana, you can use that to activate Izoni's ability to draw infinite cards.